Arch Manning is a redshirt sophomore and has now thrown 284 career passes at Texas.
By the time Quinn Ewers reached 284 career passes, he was a redshirt freshman in the middle of throwing for 369 yards and 1 TD against Washington in the Alamo Bowl, with no Bijan Robinson, behind a young and inconsistent offensive line featuring four underclassmen (Banks and Hutson were freshmen, Majors and Conner were sophomores).
By the time Sam Ehlinger reached 284 career passes, he was a sophomore in the middle of throwing for 237 yards and 2 scores against Tulsa. This was sandwiched between the demoralizing 29-34 loss to Maryland and the uplifting 37-14 win over 22nd-ranked USC that started a six-game winning streak.
By the time Garrett Gilbert reached 284 career passes, he was a sophomore in the middle of throwing for 344 yards, 2 TDs and 3 INTs in a humiliating loss to Iowa State at DKR that sounded the death knell for the 2010 season.
By the time Colt McCoy reached 284 career passes, he was a redshirt freshman in the middle of throwing for 308 yards and 2 TDs against Iowa in the Alamo Bowl, tying the NCAA record for most touchdown passes by a freshman.
By the time Vince Young reached 284 career passes, he was a redshirt sophomore in the middle of throwing for 278 yards, 1 TD and 2 INTs and rushing for 123 yards and a score during our dramatic 56-35 comeback win against Okie Lite.
Point is, the "He just needs more time and experience" excuse isn't going to cut it anymore. Ewers and Ehlinger had all shown significant, obvious improvement at the same point in their careers despite playing behind struggling offensive lines. McCoy was legitimately one of the best freshman QBs in the country (he had a much better O-line, of course). VY was still very inconsistent as a passer but had gamebreaking ability as a runner to make up for it. Note that VY, McCoy and Gilbert were all saddled with GDGD as a playcaller, and Ehlinger had to deal with Herman using him as a fullback every other play.
Only Gilbert had not shown any real improvement or any hint of a signature performance at this point in his career, and we all know how it ended. Like Manning, he had a subpar offensive line, a lack of elite WR talent, and subpar offensive playcalling to work with.